STM32 中断优先级管理（二）

NVIC中断管理相关函数主要在HAL库关键文件stm32f1xx_hal_cortex.c中定义。

中断优先级分组函数

void HAL_NVIC_SetPriorityGrouping(uint32_t PriorityGroup);

这个函数的作用是对中断的优先级进行分组，这个函数在系统中只需要被调用一次。

void HAL_NVIC_SetPriorityGrouping(uint32_t PriorityGroup)
{/* Check the parameters */assert_param(IS_NVIC_PRIORITY_GROUP(PriorityGroup));/* Set the PRIGROUP[10:8] bits according to the PriorityGroup parameter value */NVIC_SetPriorityGrouping(PriorityGroup);
}__STATIC_INLINE void NVIC_SetPriorityGrouping(uint32_t PriorityGroup)
{uint32_t reg_value;uint32_t PriorityGroupTmp = (PriorityGroup & (uint32_t)0x07UL); reg_value= SCB->AIRCR; /* read old register configuration */reg_value&=~((uint32_t)(SCB_AIRCR_VECTKEY_Msk |SCB_AIRCR_PRIGROUP_Msk)); reg_value = (reg_value|((uint32_t)0x5FAUL << SCB_AIRCR_VECTKEY_Pos) |
(PriorityGroupTmp<< SCB_AIRCR_PRIGROUP_Pos) ); SCB->AIRCR = reg_value;
}

主要通过SCB->AIRCR寄存器的值来设置中断优先级分组。

assert_param(IS_NVIC_PRIORITY_GROUP(PrioorityGroup));
断言函数，对入口参数的有效性进行判断。

#define IS_NVIC_PRIORITY_GROUP(GROUP)
(((GROUP) == NVIC_PriorityGroup_0) ||\
((GROUP) == NVIC_PriorityGroup_1) || \
((GROUP) == NVIC_PriorityGroup_2) || \
((GROUP) == NVIC_PriorityGroup_3) || \
((GROUP) == NVIC_PriorityGroup_4))

HAL_StatusTypeDef HAL_Init(void)
{/* Configure Flash prefetch */
#if (PREFETCH_ENABLE != 0)
#if defined(STM32F101x6) || defined(STM32F101xB) || defined(STM32F101xE) || defined(STM32F101xG) || \defined(STM32F102x6) || defined(STM32F102xB) || \defined(STM32F103x6) || defined(STM32F103xB) || defined(STM32F103xE) || defined(STM32F103xG) || \defined(STM32F105xC) || defined(STM32F107xC)/* Prefetch buffer is not available on value line devices */__HAL_FLASH_PREFETCH_BUFFER_ENABLE();
#endif
#endif /* PREFETCH_ENABLE *//* Set Interrupt Group Priority */HAL_NVIC_SetPriorityGrouping(NVIC_PRIORITYGROUP_2); //设置优先级分组2/* Use systick as time base source and configure 1ms tick (default clock after Reset is HSI) */HAL_InitTick(TICK_INT_PRIORITY);/* Init the low level hardware */HAL_MspInit();/* Return function status */return HAL_OK;
}

HAL_Init，这个函数非常重要，主要是对中断优先级分组，FLASH以及硬件层进行初始化。

void HAL_NVIC_SetPriority(IRQn_Type IRQn, 
uint32_t PreemptPriority, uint32_t SubPriority);
void HAL_NVIC_EnableIRQ(IRQn_Type IRQn);
void HAL_NVIC_DisableIRQ(IRQn_Type IRQn);